Prefabricated structural element for buildings

ABSTRACT

The invention relates to a prefabricated construction element for buildings in prefabricated construction, comprising a core element ( 10 ) and at least one reinforcement element ( 12 ). In order to absorb high tensile and transverse forces without the danger of developing cracks, the reinforcement element is configured as a flat material element ( 12 ) from fiber-reinforced plastic that is fixated on a lateral face ( 20 ) of the core element ( 10 ) in a form-fit and/or a material fit.

This is a Continuation of application Ser. No. 10/468,647 filed Aug. 21,2003, which in turn is a National Phase of Application No.PCT/EP02/00179, filed Jan. 10, 2002, which claims the benefit of DE 10108 375.0 and DE 101 36 633.7, filed Feb. 21 and Jul. 26, 2001,respectively. The disclosures of the prior applications are herebyincorporated by reference herein in their entirety.

DESCRIPTION

The invention relates to a prefabricated structural element forbuildings, preferably in pre-fabricated construction, with a coreelement and at least one reinforcing piece to carry tensile forces.

Panel structural elements of the above-indicated type are used inprefabricated construction as wall or ceiling elements. Usually theycontain a slab core made from lightweight concrete that is reinforcedwith a reinforcing grid embedded in the concrete slab. The purpose ofthe reinforcement is to carry any tensile or shearing forces arising inthe ceiling or wall elements, while the concrete is intended to carrycompressive forces. The strength values can be increased by addingconcrete to the slab core.

In known structural elements with reinforcing grids, a disadvantage isthat the tensile strength leaves something to be desired. Thesusceptibility of the steel reinforcing grid to corrosion is increasedbecause of the porosity of lightweight concrete, so corrosion damage canoccur prematurely. Finally, machinability is also a problem, since thereinforcement can break during drilling, leading to breakaway ofmaterial. Instability of the known prefabricated structural elementsalso causes problems with handling during transport and at theconstruction site.

Therefore the aim of the invention is to improve the known prefabricatedstructural elements so that by simple means they have high tensilestrength and long service life, and can be transported as well ashandled and worked on at the construction site without risk ofbreakaway.

The combination of features indicated in claim 1 is proposed to achievethis aim. Advantageous embodiments and further developments of theinvention are given in the subclaims.

An essential feature of the invention is that the reinforcing piece isformed as a flat stock piece made from fiber-reinforced plastic that isfixed to a long face of the core element form-fittingly and/or by usinga joining substance. A layered sheet or film can be used as a flat stockpiece for this purpose. The flat stock piece conveniently has a plasticbinder matrix and a fiber fabric or crossply embedded therein. It isadhesively affixed over an extensive area to at least one of the longfaces of the core element, preferably with an epoxy resin.

In a preferred embodiment of the invention, the flat stock piece has aplurality of projecting knob-like anchoring members on one side, bymeans of which it is engaged throughout the core element, throughopenings in the long face, and is anchored therein form-fittingly. Theanchoring members are embedded in the core element for this purpose. Inmanufacture of the structural element, the flat stock pieces are laid ina form against the wall of the form in such a way that their anchoringmembers point inward and liquid concrete is poured around them. The coreelement advantageously consists of concrete, lightweight concrete,cellular concrete, or gypsum.

The binder matrix of the flat stock can consist of a thermosettingplastic, for example from the group of epoxy resin, polyester resin,vinyl resin. The binder matrix preferably consists of a thermoplasticfrom the group of polyamide, polymethylmethacrylate, polyphenylenesulfide, polypropylene, polyethylene terephthalate, polybutyleneterephthalate, polyetherimide, styrene polymer, polyetheretherketone.The fibers of the flat stock piece are conveniently selected from thegroup of carbon fibers, glass fibers, aramid fibers, polyethylenefibers, basalt fibers, natural fibers.

In a further preferred embodiment of the invention, several reinforcingpieces are provided that are transversely interspersed in the coreelement, the widened ends of the reinforcing pieces fit flush againstthe long faces of the core element and are bonded to the at least oneflat stock piece using a joining substance, preferably adhesively. Thereinforcing pieces conveniently have a double-T shape and, for example,are made of metal, in particular aluminum or steel, or else afiber-reinforced polymer material.

In manufacture of the flat stock piece, a fiber fabric or crossply issoaked with a binder, heated up to temperature in a continuous manner,and then cooled down again and at the same time pressed, where duringthe manufacturing process knob-like anchoring pieces are formed on oneside and are preferably pressed out from the flat stock.

The prefabricated structural elements according to the invention arepreferably used as wall elements, ceiling elements, or supports forprefabricated buildings.

The invention is explained in greater detail in the following with thehelp of a schematically represented exemplary embodiment in the drawing.The drawing shows:

FIG. 1 a section through a panel structural element with form-fittinglyanchored reinforcing pieces made from fiber-reinforced plastic;

FIG. 2 a section through a structural element with internalreinforcement and reinforcing pieces made from fiber-reinforced plasticthat are adhesively bonded to the long faces.

The structural elements represented in the drawing are intended as wallor ceiling elements for buildings in pre-fabricated construction.

The panel structural elements have a core element made from concrete,lightweight concrete, cellular concrete, gypsum. Core element 10 has oneach of its long faces 20 a sheet or film type flat stock piece 12 madefrom fiber-reinforced plastic. In the exemplary embodiment shown in FIG.1, flat stock piece 12, with projecting knob-like anchoring members 14on one side, is integrally cast into core element 10 and is thusanchored form-fittingly. In the exemplary embodiment shown in FIG. 2,core element 10 additionally contains several reinforcing pieces 16transversely interspersed in the core element, the widened ends 18 ofwhich reinforcing pieces fit flush against long faces 20 of core element10. In this case, flat stock pieces 12 are adhesively bonded to longfaces 20 of the core element and ends 18 of reinforcing piece 16 withthe help of an adhesive layer 22. For this purpose, double-T shapedreinforcing pieces 16 can consist of metal such as aluminum or steel, orof a fiber-reinforced polymer material. In the latter case, flat stockpiece 12 may also be welded to ends 18 of the reinforcing pieces usingpressure and heat.

Flat stock pieces 10 serve to reinforce the core element and have thepurpose of carrying tensile and shearing forces and preventing theconcrete material from breaking away from the core element duringtransport, installation, and finishing.

In summary, we can say the following: The invention relates to aprefabricated structural element for pre-fabricated construction with acore element 10 and at least one reinforcing piece 12. So that hightensile and shearing forces can be carried with no risk of cracking, thereinforcing piece is formed as a flat stock piece 12 made fromfiber-reinforced plastic that is fixed to a long face 20 of core element10 form-fittingly and/or by using a joining substance.

1. Prefabricated structural element, comprising: a core element; and atleast one reinforcing piece that carries tensile forces, wherein thereinforcing piece is formed as a flat stock piece made fromfiber-reinforced plastic that is fixed to a long face of the coreelement form-fittingly or by using a joining substance; wherein the flatstock piece has a plurality of projecting knob-like anchoring members onone side that are engaged throughout the core element, through openingsin the long face, and is anchored therein form-fittingly; and whereinthe prefabricated structural element is utilized in a wall element,ceiling element, or support for prefabricated buildings. 2.Prefabricated structural element as in claim 1, wherein the flat stockpiece has a plastic binder matrix and a fiber fabric or crossplyembedded therein.
 3. Prefabricated structural element as in claim 1,wherein the flat stock piece is adhesively affixed over an extensivearea, to a long face of the core element.
 4. Prefabricated structuralelement as in claim 1, wherein the core element is selected from thegroup consisting of concrete, lightweight concrete, cellular concrete,or gypsum.
 5. Prefabricated structural element as in claim 1, whereinthe anchoring members are embedded in the core element.
 6. Prefabricatedstructural element as in claim 1, wherein both long faces of the coreelement have the flat stock piece made from fiber-reinforced plasticthereon.
 7. Prefabricated structural element as in claim 2, wherein theplastic binder matrix consists of a thermosetting plastic from the groupconsisting of epoxy resin, polyester resin, and vinyl resin. 8.Prefabricated structural element as in claim 2, wherein the plasticbinder matrix consists of a thermoplastic from the group consisting ofpolyamide, polymethylmethacrylate, polyphenylene sulfide, polypropylene,polyethylene terephthalate, polybutylene terephthalate, polyetherimide,styrene polymer, and polyetheretherketone.
 9. Prefabricated structuralelement as in claim 1, wherein the fibers of the flat stock piece areselected from the group consisting of carbon fibers, glass fibers,aramid fibers, polyethylene fibers, basalt fibers, and natural fibers.10. Prefabricated structural element as in claim 1, further comprisingseveral reinforcing pieces transversely interspersed in the coreelement, with widened ends of which fit flush against long faces of thecore element and are bonded to the flat stock piece using a joiningsubstance.
 11. Prefabricated structural element as in claim 10, whereinthe reinforcing piece has a double-T shape.
 12. Prefabricated structuralelement as in claim 9, wherein the reinforcing pieces are made of metalor fiber-reinforced polymer material.
 13. Reinforcing piece, comprising:a flat stock piece on which projecting knob-like anchoring members areformed on one side, wherein the reinforcing piece is utilized in a wallelement, ceiling element or support for prefabricated buildings. 14.Reinforcing piece as in claim 13, wherein the flat stock piece is formedas a sheet, film, or grid element.
 15. Method for manufacturingreinforcing pieces for prefabricated structural elements for buildings,comprising: soaking a fiber fabric or crossply with a binder, heatingthe fiber fabric or crossply to a predetermined temperature in acontinuous manner, and cooling and simultaneously pressing the fiberfabric or crossply to form the flat stock piece, wherein during themanufacturing process, knob-like anchoring members are pressed out toprotrude from the flat stock piece.
 16. Prefabricated structural elementas in claim 3, wherein the flat stock piece is adhesively affixed withan epoxy resin adhesive.
 17. Prefabricated structural element as inclaim 5, wherein the anchoring members are cast integral within the coreelement.
 18. Prefabricated structural element as in claim 10, whereinthe joining substance is an adhesive.
 19. Prefabricated structuralelement as in claim 12, wherein the metal comprises aluminum or steel.